The implementation of the MMT program in China is one of the most significant measures ever taken by the Chinese government to tackle drug use and HIV prevention challenges, and the effectiveness of these programs has implications for HIV and drug use control. Several pilot studies have identified high client drop-out rate, insufficient training of service providers and limited client service as the main challenges these programs face. We propose to take this window of opportunity to address these challenges by developing and testing an intervention, MMT PLUS, to be added on to the current MMT standard care in China. The proposed MMT PLUS intervention is designed primarily for service providers who work at MMT clinics. The proposed intervention pilot will take 2.5 years and proceed in two phases in Sichuan, China. In Phase 1, we will develop intervention manuals and supporting materials, and finalize assessment measures and implementation procedures. We will also recruit and train staff, establish quality assurance procedures and data encryption and data transfer processes. In Phase 2, we will conduct the pilot intervention across 6 MMT clinics involving 30 service providers and 150 MMT clients, and follow up at 3, 6, and 9-month period. The service provider outcomes are adherence to MMT protocol, reduction in prejudicial attitude toward MMT clients, increase in comfort working with MMT clients, and increase in motivating clients and making personalized risk management plan. The client outcomes are increased motivation to change, improved psychological and physical health, increased positive support network, and reduced HIV risk behavior. PUBLIC HEALTH RELEVANCE: China CDC, the collaborating agency for this study, is the leading force in implementing the current MMT program and has committed to develop new, innovative MMT models for nation-wide dissemination. The findings of this pilot could provide benefits for China and beyond by advancing the field through the sharing of our experience and the lessons learned in integrating a behavioral intervention into a primarily pharmacological model of methadone maintenance, and in transferring timely program development findings to country-wide implementation and policy-making.